Question

If the mass of a block is increasd 4 times . Find the factor by which it's speed should change do that it's kinetic energy remains the same​

Answer 1

Answer:

Let,

Initial velocity = u and initial mass = m

Final velocity = v and final mass = 4×m

K.E remains same.

K.E

initial

=K.E

final

2

1

mu

2

=

2

1

(4×m)v

2

u

2

=4×v

2

v

2

=

4

u

2

v=

2

u

∴ The velocity of a body should be halved, if its mass is increased by four times for the same K.E. of the body.